1) Hasn't REALLY been proven (the chemical and light gas guns are farther along; the ramac part not as much). 2) Until SpaceX, the idea of entrepreneurial spac

1) Hasn't REALLY been proven (the chemical and light gas guns are farther along; the ramac part not as much). 2) Until SpaceX, the idea of entrepreneurial space didn't exist. 3) Payload uniqueness -- this never will work for human passengers, so NASA won't fund it. The value of 1 x 100kg into LEO every hour every day for years on each launcher is not yet established.